Detection Of Arteriovenous Malformations Research Articles

Diagnostic accuracy of arterial spin labeling MR imaging in detecting cerebral arteriovenous malformations: a systematic review and meta-analysis.

Diagnostic accuracy of arteriovenous malformations (AVMs) is imperative for delineating management. The current standard is digital subtraction angiography (DSA). Arterial spin labeling (ASL) is an understudied noninvasive, non-contrast technique that allows angioarchitecture visualization and additionally quantifies cortical and AVM cerebral blood flow and hemodynamics. This meta-analysis aims to compare ASL and DSA imaging in detecting and characterizing cerebral AVMs. EMBASE, Medline, Scopus, and Cochrane databases were queried from inception to July 2022 for reports of AVMs evaluated by DSA and ASL imaging. Fourteen studies with 278 patients evaluated using DSA and ASL imaging prior to intervention were included; pCASL in 11 studies (n = 239, 85.37%) and PASL in three studies (n = 41, 14.64%). The overall AVM detection rate on ASL was 99% (CI 97-100%); subgroup analysis revealed no difference between pCASL vs. PASL (99%; CI 96-100% vs. 100%; CI 95-100% respectively, p = 0.42). The correlation value comparing ASL and DSA nidus size was 0.99. DSA and ASL intermodality agreement Cohen's k factor for Spetzler Martin Grading (SMG) was reported at a median of 0.98 (IQR 0.73-0.1), with a 1.0 agreement on SMG classification. A median of 25 arteries were detected by DSA (IQR 14.5-27), vs. 25 by ASL (IQR 14.5-27.5) at a median 0.92 k factor. ASL provides angioarchitectural visualization noninferior to DSA and additionally quantifies CBF. Our study suggests that ASL should be considered in the detection of AVMs, especially in patients with contrast contraindications or apprehension towards an invasive assessment.

ARTERIOVENOUS MALFORMATIONS OF VARIOUS LOCALIZATION: OWN OBSERVATIONS AND LITERATURE REVIEW

Currently, due to the progressive development of diagnostic technologies, the detection of arteriovenous malformations (AVM) of different anatomical locations is increasing. In this case, intraorgan AVMs are often an accidental find. The article presents the studies of domestic and foreign authors of various types of vascular anomalies, collected information about the arteriovenous malformations occurring in different organs according to the literature. The article presents our own observations of AVMs of the lungs and spleen, obtained using CT angiography.Despite the very rare occurrence of intraorgan AVMs, physicians should be aware of the possibility of such vascular pathology. It is necessary to assign additional diagnostic methods to detect AVM, primarily CT angiography.

Skeletonization method for vessel delineation of arteriovenous malformation

Cerebral arteriovenous malformation (AVM) presents a great health threat due to its high probability of rupture that can cause severe brain damage. Image segmentation alone is not sufficient to support AVM embolization procedure. In order to successfully navigate the catheter and perform embolization, the segmented blood vessels need to be classified into feeding arteries, draining veins and the AVM nidus. For this reason we address here the AVM localization and vessel decomposition problem. We propose in this paper a novel AVM localization and vessel delineation method using ordered thinning-based skeletonization. The main focus of vessel delineation is the delineation of draining veins since it is essential for the embolization procedure. The main contribution is a graph-based method for exact extraction of draining veins which, in combination with our earlier work on AVM detection, allows the AVM decomposition into veins, arteries and the nidus (with an emphasis on the draining veins). We validate the proposed approach on blood vessel phantoms representing the veins and the AVM structure, as well as on cerebral 3D digital rotational angiography (3DRA) images before and after embolization, paired with digital subtraction angiography (DSA) images. Results on AVM delineation show high correspondence to the ground truth structures and indicate potentials for use in surgical planning.

The characteristics of transcranial color-coded duplex sonography in children with cerebral arteriovenous malformation presenting with headache.

Cerebral arteriovenous malformations (AVM) are uncommon lesions. They are most often presented in childhood as intracranial hemorrhage. The aim of this report is to present the use of transcranial color-coded duplex sonography (TCCS) in detection of AVMs in children suffering headache. This report describes five pediatric patients with headache and cerebral AVM which were initially discovered by TCCS. Diagnosis was confirmed by magnetic resonance imaging and digital subtraction angiography. In all patients, TCCS showed saccular enlargement of the vessels with a multicolored pattern corresponding to the different directions of blood flow. Spectral analysis showed significantly high flow systolic and diastolic velocities and low resistance index. In this report, we describe TCCS as a valuable non-invasive, harmless, low-cost, widely available method for the detection and follow-up of hemodynamic changes of AVMs in children with headache, before and after treatment.

Role of follow-up imaging after resection of brain arteriovenous malformations in pediatric patients: a systematic review of the literature.

OBJECTIVE Pediatric patients are at risk for the recurrence of brain arteriovenous malformation (AVM) after resection. While there is general consensus on the importance of follow-up after surgical removal of an AVM, there is a lack of consistency in the duration of that follow-up. The object of this systematic review was to examine the role of follow-up imaging in detecting AVM recurrence early and preventing AVM rupture. METHODS This systematic review was performed using articles obtained through a search of the literature contained in the MeSH database, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS Search results revealed 1052 articles, 13 of which described 31 cases of AVM recurrence meeting the criteria for inclusion in this study. Detection of AVM occurred significantly earlier (mean ± SD, 3.56 ± 3.67 years) in patients with follow-up imaging than in those without (mean 8.86 ± 5.61 years; p = 0.0169). While 13.34% of patients who underwent follow-up imaging presented with rupture of a recurrent AVM, 57.14% of those without follow-up imaging presented with a ruptured recurrence (p = 0.0377). CONCLUSIONS Follow-up imaging has an integral role after AVM resection and is sometimes not performed for a sufficient period, leading to delayed detection of recurrence and an increased likelihood of a ruptured recurrent AVM.

Hereditary Hemorrhagic Telangiectasia: Arteriovenous Malformations in Children

To evaluate the clinical features in a large cohort of pediatric patients with genetically confirmed hereditary hemorrhagic telangiectasia (HHT) and to identify possible predictors of arteriovenous malformation (AVM) onset or clinical significance. Prospective cross-sectional survey of all children subjected to screening for AVMs in the multidisciplinary HHT center. All patients proved to be carriers of endoglin mutations or activin A receptor type-II-like kinase 1 mutations, defined as HHT1 and HHT2, respectively. A full clinical-radiological protocol for AVM detection was adopted, independent from presence or absence of AVM-related symptoms. Forty-four children (mean age, 10.3 years; range, 1-18) were subjected to a comprehensive clinical-radiologic evaluation. This investigation disclosed cerebrovascular malformations in 7 of 44 cases, pulmonary AVMs in 20 of 44 cases, and liver AVMs in 23 of 44 cases. Large visceral AVMs were found in 12 of 44 children and were significantly more frequent in patients with HHT1. Only large AVMs were associated with symptoms and complications. Children with HHT have a high prevalence of AVMs; therefore, an appropriate clinical and radiological screening protocol is advisable. Large AVMs can be associated with complications in childhood, whereas small AVMs probably have no clinical risk.

Pregnancy and Delivery Management in Patients With Cerebral Arteriovenous Malformation: A Single-Center Experience

We described pregnancy and delivery management in 9 patients with cerebral arteriovenous malformation (AVM). Six patients presented with intracerebral hemorrhage (ICH) during pregnancy (first hemorrhagic episode); 2 patients presented with headache; and 1 patient with incidental detection of AVM. In the 3 patients with unruptured AVM, the diagnosis was made before pregnancy. In 3 of 6 patients who presented with ICH, AVM removal was performed during pregnancy. One patient required emergency surgery for the mass effect of the hematoma, and 2 patients with Spetzler-Martin grade I and II AVMs underwent elective surgery for the prevention of rebleeding. Radiosurgery for multiple AVMs was performed after delivery in one patient. Surgical resection and radiosurgery were performed after abortion in two patients. Of 3 patients with unruptured AVM, 2 patients became pregnant after radiosurgery and conservative treatment was initiated in 1 patient for Spetzler-Martin grade V AVM. Cesarean section was performed in 5 patients (one with severe uncontrollable pregnancy-induced hypertension) and vaginal delivery in 2 patients (one with grade V AVM). Delivery by obstetrical indication was possible in patients who underwent AVM resection during pregnancy. No rebleeding during pregnancy occurred. The maternal outcome was good except for the 2 patients with consequences of the initial ICH. The fetal outcome was good except for 2 cases of abortion. Pregnancy and delivery management in patients with AVM was successful in our institution. Early surgical intervention for AVM presenting as ICH during pregnancy could prevent rebleeding and improve the maternal and fetal prognosis.

High-contrast computed tomographic angiography better detects residual intracranial arteriovenous malformations in long-term follow-up after radiotherapy than 1.5-tesla time-of-flight magnetic resonance angiography

Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are noninvasive alternatives for therapy monitoring of cerebral arteriovenous malformation (AVM). To evaluate if CTA is able to detect residual AVM in the long-term follow-up after radiotherapy when time-of-flight (TOF) MRA could no longer detect a remaining nidus. 18 patients with intracranial AVM were included between November 2005 and August 2007 who were scheduled for CTA (16-slice CT, 1-mm slice thickness, 90 ml iomeprol 400 mg I/ml, 4 ml/s) in the follow-up of radiotherapy. In these patients, MRA (3D-TOF, and bolus tagging at 1.5 T) could no longer detect a remaining nidus. The previously performed MRA (median time between CTA and MRA, 2.5 months) described total obliterations in 14 and subtotal obliterations in two AVM cases. Two MRA diagnoses were inconclusive due to artifacts. CTA (median time after therapy, 28 months; range, 5-66 months) could provide a diagnosis in all cases, but confirmed the MRA diagnosis only in 50% of the cases. A residual nidus was shown in an additional six cases, and subtotal obliteration in another three cases. The interval between radiotherapy and the follow-up examination was significantly different (P<0.05) between false- and true-negative MRA examinations (median, 18 vs. 30 months). High-contrast CTA is a sensitive tool in the detection of AVM and is able to identify residual AVM after radiotherapy even if previously performed TOF MRA at 1.5 T shows total obliteration.

Novel mutations inENGandACVRL1identified in a series of 200 individuals undergoing clinical genetic testing for hereditary hemorrhagic telangiectasia (HHT): correlation of genotype with phenotype

Hereditary hemorrhagic telangiectasia (HHT; Osler-Weber-Rendu disease) is an autosomal dominant disease characterized by arteriovenous malformations ranging from cutaneous and mucous membrane telangiectasias to more severe pulmonary, gastrointestinal, and cerebral arteriovenous malformations (AVMs). Acute complications from bleeding or pulmonary shunting may be catastrophic. However, when diagnosed early, the complications can usually be prevented. Mutations in two genes, Endoglin (ENG) and activin receptor-like kinase 1 (ACVRL1 or ALK1) have been associated with HHT. We describe the results of mutation analysis on a consecutive series of 200 individuals undergoing clinical genetic testing for HHT. The observed sensitivity of mutation detection was similar to that in other series with strict ascertainment criteria. A total of 127 probands were found, with sequence changes consisting of 103 unique alterations, 68 of which were novel. In addition, eight intragenic rearrangements in the ENG gene and two in the ACVRL1 gene were identified in a subset of coding sequence mutation-negative individuals. Most individuals tested could be categorized by the number of HHT diagnostic criteria present. Surprisingly, almost 50% of the cases with a single symptom were found to have a significant sequence alteration; three of these reported only nosebleeds. Genetic testing can confirm the clinical diagnosis in individuals and identify presymptomatic mutation carriers. As many of the complications of HHT disease can be prevented, a confirmed molecular diagnosis provides an opportunity for early detection of AVMs and management of the disease.

ENDOGLIN MODULATES COUPLING OF ENOS ACTIVITY AND VASCULAR MYOGENIC REACTIVITY

To evaluate the clinical features in a large cohort of pediatric patients with genetically confirmed hereditary hemorrhagic telangiectasia (HHT) and to identify possible predictors of arteriovenous malformation (AVM) onset or clinical significance.Prospective cross-sectional survey of all children subjected to screening for AVMs in the multidisciplinary HHT center. All patients proved to be carriers of endoglin mutations or activin A receptor type-II-like kinase 1 mutations, defined as HHT1 and HHT2, respectively. A full clinical-radiological protocol for AVM detection was adopted, independent from presence or absence of AVM-related symptoms.Forty-four children (mean age, 10.3 years; range, 1-18) were subjected to a comprehensive clinical-radiologic evaluation. This investigation disclosed cerebrovascular malformations in 7 of 44 cases, pulmonary AVMs in 20 of 44 cases, and liver AVMs in 23 of 44 cases. Large visceral AVMs were found in 12 of 44 children and were significantly more frequent in patients with HHT1. Only large AVMs were associated with symptoms and complications.Children with HHT have a high prevalence of AVMs; therefore, an appropriate clinical and radiological screening protocol is advisable. Large AVMs can be associated with complications in childhood, whereas small AVMs probably have no clinical risk.

The New York Islands AVM Study: design, study progress, and initial results.

Prospective population-based data on the incidence of brain arteriovenous malformation (AVM) hemorrhage are scarce. We studied lifetime detection rates of brain AVM and incident AVM hemorrhage in a defined population. The New York islands (ie, Manhattan Island, Staten Island, and Long Island) comprise a 9,429,541 population according to the 2000 census. Since March 15, 2000, all major New York islands hospitals have prospectively reported data on consecutive patients living in the study area with a diagnosis of brain AVM and whether the patient had suffered AVM hemorrhage. Patients living outside the ZIP code-defined study area were excluded from the study population. As of June 14, 2002, 284 prospective AVM patients (mean+/-SD age, 35+/-18 years; 49% women) were encountered during 21,216,467 person-years of observation, leading to an average annual AVM detection rate of 1.34 per 100,000 person-years (95% CI, 1.18 to 1.49). The incidence of first-ever AVM hemorrhage (n=108; mean age, 31+/-19 years; 45% women) was 0.51 per 100,000 person-years (95% CI, 0.41 to 0.61). The estimated prevalence of AVM hemorrhage among detected cases (n=144; mean age, 33+/-19 years; 50% women) was 0.68 per 100,000 (95% CI, 0.57 to 0.79). Our prospective data, spanning 27 months, suggest stable rates for AVM detection and incident AVM hemorrhage. Approximately half of AVM patients may suffer intracranial hemorrhage.

Combining stereotactic angiography and 3D time-of-flight magnetic resonance angiography in treatment planning for arteriovenous malformation radiosurgery

Purpose: This study was initiated to evaluate the advantages of using three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), as an adjuvant to conventional stereotactic angiography, in obtaining three-dimensional information about an arteriovenous malformation (AVM) nidus and in optimizing radiosurgical treatment plans. Methods and Materials: Following angiography, contrast-enhanced MRI and MRA studies were obtained in 22 consecutive patients undergoing Gamma Knife radiosurgery for AVM. A treatment plan was designed, based on the angiograms and modified as necessary, using the information provided by MRA. The quantitative analysis involved calculation of the ratio of the treated volume to the MRA nidus volume (the tissue volume ratio [TVR]) for the initial and final treatment plans. Results: In 12 cases (55%), the initial treatment plans were modified after including the MRA information in the treatment planning process. The mean TVR for the angiogram-based plans was 1.63 (range 1.17–2.17). The mean coverage of the MRA nidus by the angiogram-based plans was 93% (range 73–99%). The mean MRA nidus volume was 2.4 cc (range 0.6–5.3 cc). The MRA-based modifications resulted in increased conformity with the mean TVR of 1.46 (range 1.20–1.74). These modifications were caused by MRA revealing irregular nidi and/or vascular components superimposed on the angiographic projections of the nidi. In a number of cases, the information from MRA was essential in defining the nidus when the projections of the angiographic outlines showed different superior and/or inferior extent of the nidus. In two cases, MRA revealed irregular nidi, correlating well with the angiograms and showed that the angiographically acceptable plans undertreated 27% of the MRA nidus in one case and 18% of the nidus in the other case. In the remaining 10 cases (45%), both MRI and MRA failed to detect the nidus due to surgical clip artifacts and the presence of embolizing glue. Conclusions: The 3D TOF MRA provided information on irregular AVM shape, which was not visualized by angiography alone, and it was superior to MRI for defining the AVM nidus. However, when imaging artifacts obscured the AVM nidus on MRI and MRA, angiography permitted detection of AVM. Utilizing MRA as a complementary imaging modality to angiography increased accuracy of the AVM radiosurgery and allowed for optimal dose planning.

Sensitivity of brain scanning in the detection of arteriovenous malformations.

99mTc pertechnetate brain scans and cerebral angiograms were correlated in 10 cases of arteriovenous malformation. Lesions 2.7 em or more in mean diameter were detected by rectilinear scanning technique after the injection of 99mTc pertechnetate intravenously. Limitations of detection appear to be more dependent on size than on location.